Timing relay



TIMING RELAY Filed March 29, 1934 mmnnnmulmlm /%TNESSES: INVENTOR j I g awry Patented Oct. 22, 1935 UNITED STATES PATENT OFFICE TIMING RELAY Pennsylvania.

1 Application March 29, 1934, Serial No. 717,982

8 Claims.

My invention relates, to timing devices for use in connection with direct current apparatus and circuits, and particularly to such timing devices of the type in which a vibrating mechanical element is used to control the timing operation.

It is an object of my invention to provide a novel direct-current timing device of the type indicated above which shall employ a motive element of a type and desimi suitable for use in alternating current timing devices also.

Another object of my invention is to provide a direct current timing relay of the type indicated above, in which the principal motive ele-- ment shall be an alternating-current motor and in which no additional electro-magnetic element shall be required to drive the vibrating mechanical element.

A further object of my invention is to provide a novel relay of the type indicated above, in which the leakage flux of the motive element shall be utilized to drive the vibrating mechanical element.

Other objects of my invention will become evident from the following detailed description taken in conjunction with the accompanying drawing in which;

Figure 1 is a diagrammatic view of a timing relay embodying my invention.

Figs. 2 and 3 are diagrammatic views of motor .armatures which may be used in the practice of my invention; and,

Fig. 4 is a diagrammatic view of a modification of the relay shown in Fig. 1.

Referring to the'drawing in detail, an alternating-current motor I, of any suitable constant speed or substantially constant speed type, is mechanically connected by means of a gear train 2 to a contact arm 3, for driving the latter. The motor I comprises the usual stator la having a stator winding lb and suitable means for obtaining quadrature flux such as a pair of shading coils la, and a main armature or rotor Id. The armature ld may be of any suitable self-' starting type. i

The contact arm 3 is biased against a stop 4 by any suitable means, such as a spring 5, and is operable away from the stop into engagement with suitable main contact members 6. The stop 4 is preferably adjustable through a range of angular positions by means of a timing lever 1, arranged to be frictionally held in any angular position to which it may be adjusted, in a manner well understood in the art.

A vibratory reed 9, of magnetic material, is mounted in a position to be attracted by the leakage flux of the stator la. The reed 9 is arranged to periodically open a pair of normally closed auxiliary contact members l0, connected in a direct current circuit which includes the stator winding lb, a suitable source of direct cur- 6 rent II and a'switch l2. 1

A condenser I3 is connected in parallel with the stator winding lb, to form a resonant circuit therewith. The condenser I3 is preferably of such capacitance value that the natural period 10 of the resonant circuit is substantially the same as that of the mechanical system comprising the reed 9, or is a harmonic or sub-harmonic thereof.

The operation of the above described apparatus may be set forth as follows: Upon closure of the switch l2, a current commences to build up in the inductive stator winding lb, and the main flux and leakage flux of the stator la' increase. When the leakage flux of the stator la becomes sufliciently great, the reed 9 is attracted thereby opening the circuit through the stator winding lb. The energy inductively stored in the stator la now discharges into the condenser l3, and an oscillatory transfer of power commences in the resonant circuit, in a manner well understood in the art.

In response to the oscillatory current in the stator winding lb, the rotor Id commences to turn, and the reed 9 commences to vibrate. A steady state condition is reached almost immediately in which the current flowing in the stator winding lb consists of a pulsating direct component which traverses the battery II and an alternating component which circulates in the local circuit of the stator winding lb and condenser l3. The contact arm 3 rotates counterclockwise at a uniform speed and engages the contact members 6 at the expiration of a definite time interval. The time element of the relay may be adjusted by changing the angular position of the timing lever 1.

Referring to Fig. 2, which shows a preferred form of self-starting armature for the motor I of Fig. 1, the core I5 is of such shape as to provide a number of salient poles which is an even multiple of the number of stator poles, for example twelve armature salient poles. A squirrel cage winding I6 is provided in the slots between poles. The parts are designed in such manner that the synchronous speed of the motor corre- 'sponds to that of a l2-pole motor, rather than which may be used in the motor of Fig. 1 for operation upon the hysteresis principle.

Fig. 4 shows a modification of the relay of Fig. 1, in which a separate electro-magnet I! is provided for operating the vibrating reed 9. The arrangement of Fig. 4 is otherwise the same as that Fig. 1, and its operation will be obvious from that described above.

I do not intend that the present invention shall be restricted to the specific structural details, arrangement of parts or circuit connections herein set forth, as various modifications thereof may be eflected without departing from the spirit and-scope of my invention. I desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. In a direct-current timing device, an alternating-current motor having a winding, a rotary armature operable at substantially constant speed in response to periodic energization of said winding, and starting means effective to produce a quadrature excitation component in said motor when said winding is periodically energized at a predetermined frequency, contact members, direct-current energizing means including a circuit controlled by said contact members for energizing said winding, and means for operating said contact members in response to a periodically varying electrical condition of said circuit, said last-mentioned means including a vibratory mechanical element tuned to said irequency.

2. In a. direct-current timing device, an alterhating-current motor having a stator and a rotor, said stator having a main winding and an auxiliary winding for producing quadrature excitation, contact members, dlrect-current energizing means including a circuit controlled by said contact members for energizing said winding, and means for operating said contact members in response to a periodically varying electrical condition of said circuit, said last-mentioned means including a vibratory mechanical element tuned to said frequency.

3. In a direct-current timing relay, an electromechanical energy-translating system having a winding and a movable element operable at substantially constant speed in response to a periodically varying condition of energization of said winding, an auxiliary element movable periodically in response to said periodically varying condition, main contact members controlled by said movable element, auxiliary contact members controlled by said auxiliary element, and direct-current energizing means for said winding controlled by said auxiliary contact members.

4. In a direct-current timing relay, an alternating-current motor having a stator magnetic structure, winding means for energizing said structure, and a main armature operable at substantially constant speed in response to a pcriodically varying condition of energization of said structure, a vibratory auxiliary element operable in response to leakage flux of said struc ture, main contact members controlled by said armature, auxiliary contact members controlled by said auxiliary element, and direct-current energizing means for said winding means con- 5 trolled by said auxiliary contact members.

5. In a direct-current timing relay, a resonant electrical system including an electro-mechanical energy translating element, a vibratory mechanical system having substantially the same natural period as said electrical system, said mechanical system including a movable element, main contact member's controlled by said electro-mechanical energy translating element, auxiliary contact members controlled by said movit able element, and direct-current energizing means for said electrical system controlled by said auxiliary contact members.

6. In a direct current timing relay, an alternating-current motor of a synchronous type having a stator magnetic structure, winding means for energizing said structure, and a rotor operable at constant speed in response to a periodically varying condition of energization of said structure, a vibratory auxiliary element operable in response to leakage flux of said structure, main contact members controlled by said rotor, auxiliary contact members controlled by said auxiliary element, and direct-current energizing means for said winding means controlled by said auxiliary contact members.

7. In a direct-current timing relay, magnetic structure forming a main magnetic circuit including a main air gap and a second magnetic circuit including a second air gap, a winding interlinked with both of said magnetic circuits,

a rotor in said main air gap operable at substantially constant speed in response to a periodically varying condition of energization of said winding, a vibratory mechanical system having a magnetic auxiliary element in said second air gap, main contact members controlled by said rotor, auxiliary contact members controlled by said auxiliary element and directcurrent energizing means for said winding controlled by said auxiliary contact members.

8. In a direct current timing relay, a sub-synchronous motor having a stator magnetic structure, a winding for energizing said structure and a rotor operable at constant speed in response to a periodically varying condition of energization of said structure, a vibratory mechanical system comprising a magnetic armature element in a leakage flux path of said structure and a resilient member for supporting said element, main contact members controlled by said rotor, auxiliary contact members controlled by said armature element,- a condenser connected in parallel to said winding, 9. direct-current source, and conductors connecting said winding and condenser in parallel in a circuit including said auxiliary contact members and said source.

ROY J. WENSLEY. 

